大鼠脑缺血再灌注后神经细胞的细胞周期特征的比较研究

Cell cycle characteristics between astrocytes and neurons in rat models following focal cerebral ischemia

目的比较观察大鼠局灶性脑缺血后星形胶质细胞和神经元细胞周期的变化特征。方法采用线栓法大鼠大脑中动脉栓塞模型,利用流式细胞技术检测假手术组和缺血再灌注后不同时间点各组大脑皮层和海马中星形胶质细胞和神经元细胞周期的异常激活和动态变化。结果缺血后大脑皮层中神经元24h时即发生明显细胞周期变化,而3d时进入细胞周期的星形胶质细胞才明显增加;海马中星形胶质细胞却先于神经元进入细胞周期,于24h时细胞周期即发生明显变化,与假手术组比较有显著差异(P<0.01)。结论在不同脑区星形胶质细胞和神经元两者对缺血性脑损伤的敏感性互不相同,并且不同脑区的星形胶质细胞对缺血性脑损伤的敏感性也有不同,脑缺血后2种细胞均出现细胞周期的异常激活。

Objective To study the difference of cell cycle characteristics between astrocytes neurons following the sham-operation and focal cerebral ischemia in rats. Methods Isehemia/reperfusion injury was induced by temporary middle cerebral artery occlusion（MCAO）. Experimental rats were sacrificed on day1, 3, 7, and 14 of reperfusion, then the cell cycle was detected by flow eytometry（FCM）. Results After MCAO, in the cortex the ratios of neurons re-entering cell cycle significantly increased at day 1 of reperfusion, but at day 3 astroeytes were activated to enter into new cell cycle events. Whereas in the ipsilateral hippocampus of rats at day 1 of reperfusion, astroeytes proceeded to enter into cell cycle, and a statistically significant increase was observed compared with the sham-operation groups（P〈0.01）. Conclusions In addition to a differential sensitivity between astrocytes and neurons to ischemic injury, there is also a differential sensitivity among astroeytes from different brain regions. And re-entering into cell cycle occurred in both astrocytes and neurons after MCAO.